Pickup trucks are in widespread use for carrying loads of varying size. When the load is small, it is wise to have it secured in some way so that it does not shift and slam into a side or end of the truck when it rounds a tight curve, accelerates or comes to an abrupt stop. U.S. Pat. No. 6,523,043 to the Applicants herein for an adjustable cargo gate system addressed that need, permitting a load to be secured at any place along the bed of the truck. For a load that is longer than the truck bed, it is desirable to extend the truck bed by lowering the tailgate and providing means to prevent the load from falling out of the back of the truck. In the prior art, there are a number of patents that have provided enclosures for the lowered tailgate to prevent a load from falling off the back of the truck. U.S. Pat. Nos. 5,700,047 and 6,113,173 to Leitner et al. provide such an enclosure. It has only two operating positions: over the tailgate beyond the rear end of the truck bed, and 180° from that position spaced forward from the rear end of the bed and the tailgate because the ends of the enclosure are pivotably fixed to the sides of the truck, limited the structure to rotate through 180°. Other pivoting tailgate enclosures are provided by U.S. Pat. No. 6,283,525 to Morse, U.S. Pat. No. 6,719,345 to Ootsuka et al. and U.S. Pat. No. 6,540,123 to Kmita et al. Like Leitner, Morse has only two operating positions, whereas Kmita has only one. Ootsuka teaches that the enclosure can be rotated to a 90° configuration or a 180° position. U.S. Pat. No. 6,322,125 to Bauer is for an enclosure convertible to a ramp. None of these inventions has the versatility of being secured anywhere along the bed of the truck or the tailgate.
Accordingly it is an object of this invention to provide an improved version of the adjustable cargo gate system of U.S Pat. No. 6,524,043 having alternative end sections to the cargo gate which can enclose an opened tailgate, thereby extending the truck bed, and which can be easily removed and stored in the corners of the truck bed, to improve and simplify the sliding braces which support the cargo gate in an upright position, and to provide a simpler form of the tracks on which the cargo gate is positioned.